package registrar

import (
	"context"
	"encoding/json"
	"fmt"

	"github.com/google/uuid"
	svc "go.fixergrid.net/servicedemon/pkg/registrar/internal/services"
)

const APPROVAL_TOPIC = "net.fixergrid.events.app.approved"

type ApprovalListener struct {
	svc.ApprovalRequester
	svc.PubSub
	svc.AppRepo
	log internalLog
}

type option func(r *ApprovalListener)

func OptionLog(l logger) option {
	return func(r *ApprovalListener) {
		r.log = internalLog{l}
	}
}

func NewApprovalListener(ps svc.PubSub, requester svc.ApprovalRequester, options ...option) ApprovalListener {
	out := ApprovalListener{
		PubSub:            ps,
		ApprovalRequester: requester,
	}

	for _, opt := range options {
		opt(&out)
	}
	return out
}

func (a ApprovalListener) Run(ctx context.Context) {
	newAppEvents := a.Subscribe(REGISTRATION_TOPIC)
	approvalEvents := a.Subscribe(APPROVAL_TOPIC)
	for {
		select {
		case <-ctx.Done():
			return
		case event := <-newAppEvents:
			msg, err := readMessage(event)
			if err != nil {
				a.log.Printf("failed to read message: got '%s': %v", event, err)
			}
			a.SendApprovalRequest(msg["name"])
		case event := <-approvalEvents:
			msg, err := readMessage(event)
			if err != nil {
				a.log.Printf("approvalevent: failed to read message: got '%s': %v", event, err)
			}
			id := uuid.MustParse(msg["id"])
			a.HandleApprovedRequest(id)
		}
	}
}

func (a ApprovalListener) SendApprovalRequest(name string) {
	a.log.Printf("sent approval message for [%s]", name)
}

func (a ApprovalListener) HandleApprovedRequest(id uuid.UUID) {
	res, err := a.ApproveApp(id)
	if err != nil {
		a.log.Printf("ERROR: couldn't approve request: %v", err)
		return
	}

	a.log.Printf("approved application [%s]", res.ID)
}

func readMessage(event string) (map[string]string, error) {
	out := map[string]string{}

	err := json.Unmarshal([]byte(event), &out)
	if err != nil {
		return nil, fmt.Errorf("readMessage: %w", err)
	}
	return out, nil
}